The Virtual Pipe Organ Explained

Development of the pipe organ

Before discussing the relatively recent phenomenon of the Virtual Pipe Organ, it may be helpful to start with a history of the pipe organ itself (albeit a very brief and incomplete one!) The organ is quite an ancient instrument, going back at least to Roman times, and considerably predating the piano which didn't become firmly established until the 18th century. The basic idea of the organ is to arrange a series of pipes on a box, with a means of controlling the air supply to each pipe. An organ pipe is rather like a recorder in the way it produces sound, but while a recorder can produce a range of notes depending on which holes are covered, an organ pipe only produces a single note.

From crude beginnings, the organ grew to achieve a high level of sophistication. A particularly significant period was the 17th century "baroque" era, when a number of composers , most notably Johann Sebastian Bach, wrote major works for the instrument which have remained firmly established in its repertoire to the present day. The organ of Bach's time consisted of numerous "ranks" of pipes, providing different pitches and timbres, and capable of being combined in various ways - not so much an instrument as a collection of instruments. To give the player more control, the organ was divided into a number of divisions, each with its own keyboard. A further "pedal keyboard" was provided to allow the player's feet to be used.

A pattern for pipe organ design was now firmly established, but the organ continued to grow in size and complexity and expressiveness. By the 19th century we find builders such as Cavaille-Coll in France and Willis in England building large, "romantic" instruments which rivaled the symphony orchestra in power and tonal range. But building larger organs was not without its problems in an age before the widespread availability of electricity. It was difficult to ensure an adequate air supply when the motive force was human muscle (and what a boring job it must have been!) And with more pipes to control, the organ's keys became harder to operate, especially when two divisions were coupled together. Instead of a simple mechanical connection between key and pipe, it became necessary to utilise air pressure to amplify the force, as in the "pneumatic lever action" .

During the 20th century, electricity was widely exploited by organ builders, both to provide a reliable supply of wind, and to give organists more control over their instruments. For a while, organ development continued along two parallel paths. On the one hand there was the church or classical organ with a tradition going back centuries. On the other, the new cinema or theatre organ which was used in dance halls and in cinemas to accompany silent films. By using clever switching systems, the theatre organ made fewer pipes go farther. With its flamboyant appearance, a sound palette designed to have popular appeal, percussion instruments and sound effects, the newcomer could hardly have been more different from its straight-laced cousin. Devotees of the classical organ looked on disapprovingly!

Even within the classical camp, controversy was afoot. There was something of a backlash, a feeling that the organ had strayed too far from its roots. The complicated electrical and/or pneumatic systems which allowed the player to control countless pipes effortlessly did not give the same touch, the same intimacy of control, which the old mechanical ("tracker") actions gave. Many felt the organ had become corrupted by technology. It had become too orchestral in its sound, and there were too many transcriptions in its repertoire. They longed to return to the tonal purity of an earlier age. They wanted organs which could perform the great works of Bach authentically. Once more it became fashionable to build smaller organs with tracker actions.

The details of pipe organ specification and design still provoke strong feelings to the present day, and any new pipe organ which is built is sure to attract its critics as well as its admirers. However, I think it's true to say that, by and large, a more pluralistic attitude now prevails. People are more open to hearing a wider range of music on a wider range of instruments - whether they be from the baroque, the romantic or the theatre tradition. And, as we shall see later, organists can now experience playing a wide range of instruments more easily than ever before, thanks to the development of the virtual pipe organ.

The electronic or "pipe-less" organ

From around the middle of the 20th century it became feasible to use electricity not just to control an organ, but to generate the sound. These "analogue" electronic organs used valves at first, and later transistors. One of the earliest types was the Hammond, which had a distinctive sound all of its own. When there was an attempt to reproduce the sounds of the pipe organ, the results were usually closer to the theatre organ than the classical sound. Electronic classical organs were made, and were used in churches, and also for church organists to practise upon at home, but the sound was never terribly convincing. They were always considered a poor substitute for the real thing.

It was only towards the end of the 20th century that classically voiced electronic organs really came into their own. Known first as "computer organs" and later as "digital organs", a new generation of pipe-less instruments could produce sounds so close to the real thing that it wasn't always easy to tell the difference. Thanks to major advances in computer technology, electronic circuitry could now do far more than make something vibrate at a certain frequency - it could store and process vast amounts of information. This in turn led to the idea of "sampling". Instead of creating sounds synthetically, the makers of digital organs could record pipe sounds from some of the world's most outstanding pipe organs, and incorporate the very same sounds into their own instruments. In view of the high quality of the sound produced, as well as the economic advantages of lower initial cost and minimal maintenance requirements, it was inevitable (if slightly sad) that many churches would decide to replace their aging pipe organ with a digital alternative. The vast majority of organ enthusiasts would still maintain that nothing compares to the real thing, but one well-known performer has gone on record saying he prefers playing digital instruments.

The Virtual Pipe Organ

The Virtual Pipe Organ (VPO) is the most recent development in organ technology, only gaining momentum during the early years of the 21st century. The basic idea is that processing power is supplied by the ubiquitous personal computer, rather than by a dedicated processor supplied by an organ manufacturer. The ramifications of this change are quite far-reaching.

Two factors have undoubtedly played a large part in the emergence of this new approach. One is the exponential increase in the processing power and memory capacity of the typical personal computer. The other is the widespread adoption of the MIDI protocol which allows electronic musical devices to communicate with each other. In some ways a VPO installation can seem quite similar to the sort of digital organ described above, but significantly, the design and specification of the organ is devolved down from the manufacturer to the end user. Instead of buying a complete organ from a single manufacturer, the user is free to "shop around" for the hardware and software of their instrument. To some extent, they become their own organ builder. The following major components are all likely to come from different suppliers:

- Personal computer

- Virtual Pipe Organ software

- Organ sample set(s)

- MIDI keyboards, pedalboard and other console equipment

- Amplification and speaker systems

This mix-and-match approach clearly allows enormous flexibility - to the extent that no two VPO installations are likely to be exactly the same. It also provides flexibility of cost - wealthy connoisseurs can spend a small fortune in their pursuit of excellence, the impecunious can get an organ up and running for a surprisingly modest outlay, especially if (as is often the case) a suitable computer is already available. There are already a large number of organ sample sets available, allowing the user to play not one but a wide range of organs, covering all styles, regions and periods.

In view of these advantages, it seems inevitable that the VPO will continue to increase in popularity for the foreseeable future, but not to the extent that it supplants the off-the-shelf digital organ completely. Not everyone wants to get involved with configuring software and setting MIDI output channels - there will always be a demand for something which can simply be switched on and played. Perhaps manufactured organs will become more "virtual" in the future. Or maybe we will see a large-scale merging of the technologies as the mainstream manufacturers try to "muscle in" on the VPO market. However, since predicting the future is a mug's game, I'll leave it for someone else to do ...

Setting up your own Virtual Pipe Organ

As already described, many virtual pipe organ installations start from very humble beginnings, and gradually evolve into something quite special. If you would like to set up your own VPO, the following is just one of the ways you might go about it.

The first thing you need is a computer, and the chances are you already have one which is suitable. It should be a reasonably modern computer, but not necessarily a high-spec model, certainly not to begin with. It will need a working sound card, of course, and again you don't need the best money can buy. You can start with the one it came with, and maybe upgrade to a better one in the future. A broadband connection is highly desirable, so you can download the VPO software and sample sets. These tend to come in very large files!

When it comes to the question of software, your choice will be influenced by the type of organ you wish to play. Hauptwerk is undoubtedly the leading version for classical organs, but Miditzer is a worthwhile alternative if you're more drawn towards the theatre organ. (I enjoy using both of them). Free versions of both can be downloaded from the respective websites (see our "Links" page.) Miditzer has just the one Wurlitzer sample set which is permanently loaded. Hauptwerk comes with one romantic English organ (St Anne's Moseley) to get you started.

Having installed your virtual organ on your computer, you next need some sort of MIDI input device to play it with. If you have keyboard such as a Yamaha or Casio with MIDI output you could use that, but you will probably need to buy a special adaptor to connect the keyboard's MIDI port to one of your computer's USB ports. A better solution is to get hold of a MIDI controller keyboard which will plug directly into the computer's USB port. These come in various makes and sizes - the one I am most familiar with is the M-Audio Keystation 61es which is not too expensive but extremely reliable, and the same size as a standard organ keyboard (5 octaves) . Second-hand examples come up regularly on Ebay.

At this point you should have a modest but functional virtual pipe organ for a very small outlay (less than £200). But what if you press the keys and nothing happens? Chances are your software isn't configured correctly. A common cause of problems is that the software is expecting MIDI input on one channel, and the keyboard is sending it on a different channel. Remember too that the virtual organ, just like a "real" organ, doesn't make any sound if all the stops are pushed in!

Another common problem experienced by beginners is a time delay between pressing the key and hearing the note. This is known as "latency" and can be quite off-putting. The way to eliminate it, or at least to minimise it, is to reduce the size of the sound output buffer as much as you can without causing distortion. If using Hauptwerk, you should also make sure that the ASIO4ALL sound driver is installed.

Your basic virtual pipe organ is sure to give you a great deal of innocent pleasure, but human nature being what it is, you'll soon be itching to upgrade it. The exact order in which you do this is up to you, and may be influenced by available funds. We'll consider each aspect in turn:

Console: You'll soon feel the need for at least two keyboards. This will involve buying a second MIDI controller keyboard and perhaps arranging some sort of stand to hold the two keyboards in a suitable position. (Alternatively, you could buy one of our two or three keyboard stacks with pistons- just a thought!) Next you'll want a MIDI pedalboard. 2nd hand ones do come up on Ebay from time to time, but not in great quantity. They can be bought new, of course (and we hope to have one available soon). If your pedalboard includes one or more expression pedals and some toe pistons then you're well on your way to having a fully equipped console.

One of the more difficult things to arrange is physical control of the virtual organ's stops, and many users manage without this facility altogether, though they wouldn't want to manage without pistons. To paraphrase Oscar Wilde: Give me enough pistons and I'll manage without stops. Hauptwerk's registration sequencer is one way of avoiding direct stop manipulation, but if you want to be more spontaneous with your registrations, then a computer touch screen can be used.

There are many console alternatives available from a number of different suppliers. You could even buy a complete 2nd hand organ with a MIDI OUT facility.

Software: To take Miditzer first, the free version is fully functional, so you won't necessarily feel the need to upgrade it, particularly if you have a two-manual console. If you upgrade to a three-manual console then you will probably wish to upgrade to the three manual version of the software too. This is available for a 60 day free trial, after which a donation of 100 US dollars is required, to be used for theatre organ restoration projects. This version also gives you some additional ranks, including piano.

The free version of Hauptwerk is quite heavily restricted, so you may feel the need to upgrade fairly early on. The "basic" edition currently costs 179 euros, and the "advanced" edition 431 euros. However, as the product ships from the USA, UK buyers must expect to pay VAT and import tax on receipt. The website lists the differences between the versions.

Sample sets: This consideration does not apply to Miditzer as you get the software and the sample set as a package. Things are very different with Hauptwerk - a considerable choice of sample sets exists, mostly from third-party suppliers. Making recordings of organ pipes and selling sample sets has now become a business in its own right. The Hauptwerk website contains a useful database, and it's possible to set search criteria, such as builder, or number of manuals. Inevitably, some of most impressive sample sets are quite expensive, but there are a few free ones, others which only require a small donation, and others which are available in cut-down evaluation versions so you can try before you buy. If you have a leaning towards English organs, you should certainly check out the products of Lavender Audio (see our "Links" page). The 1809 Joseph Hart organ at Little Waldingfield just oozes character, while the Old Independent Church at Haverhill is a fine 3-manual instrument by J.J.Binns. Silver Octopus Studios (also on our "Links" page) produce a range of sample sets with an emphasis on the work of Willis.

Computer: It's surprising how much can be achieved with quite a modest computer, but sooner or later you may feel the need to upgrade. A common scenario is that a sample set you would like to use requires more memory than your computer can provide. Even in this situation, it may be possible to avoid an upgrade by installing the sample set with certain options disabled. Hauptwerk provides a high level of control over the installation process. This comes at a price, of course - the more options you disable, the more you compromise the final sound quality.

Sometimes a memory upgrade can be accomplished simply by buying extra memory and plugging it in. Crucial is a website which specialises in this area (see our "Links" page). This is something you can do yourself, if you're brave enough (but it might be a good idea to back up your files first!) However, the important factor is not how much physical memory is present, but how much of it can be addressed by the operating system. For example if you have a computer with 2Gb memory running 32 bit Windows, and you add 2Gb of extra memory, the total usable memory will be approximately 3.5 Gb, not 4Gb as you might expect. It's necessary to change to a 64 bit operating system to go past this limit.

If you're considering upgrading to a new computer, one point to bear in mind is that Hauptwerk is primarily developed on Apple computers and then adapted for PC's. Apple computers are recommended because they handle sound in a more direct way, so they don't experience the latency problems which can occur with PC's. However, as I've only ever used Hauptwerk on PC's, I can't comment further.

Amplification and speakers: If the speakers which came as part of your computer aren't really up to serious musical use, you may wish to upgrade them. Another approach, which I have used extensively, is to buy a simple cable (available at all computer stores) which allows you to connect the audio output from your computer to the "AUX" input of a music system. Other VPO users go very much farther, making full use of Hauptwerk's multi-channel output facility, and having numerous speakers strategically positioned for ultimate realism, but this requires the "advanced" edition of the software.

That concludes our brief explanation of what a VPO is, and how to go about getting one. You can find plenty more information at the websites on our "Links" page, some of which have discussion forums. Most people involved in this area are only too happy to share their experiences and offer advice to newcomers.